cPanel (cpsrvd / cpsrvd-ssl) fails at random

Cpsrvd/cpsrvd-ssl fails at random. There is no particular pattern. Today (thankfully) it happened on different server (until today only one had that problem) and I managed to get this from the error_log :
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(internal death) Mon Feb 12 21:21:49 2007 [6918] error: Undefined subroutine &main::Rvtheme_xskinUseag called at (eval 79) line 1.
eval 'Rvtheme_xskinUseag(@RARGS);' called at cpanel.pl line 540
main::exectag('<cpanel Rvtheme="xskinUseag(1)">') called at cpanel.pl line 3493
main::dotag(undef) called at cpanel.pl line 3407
main::parsehtml('GLOB(0x8ea2040)') called at cpanel.pl line 1584
main::doinclude('cells/*.html', 1) called at cpanel.pl line 552
main::exectag('<cpanel dynamicinclude="cells/*.html">') called at cpanel.pl line 3493
main::dotag(undef) called at cpanel.pl line 3407
main::parsehtml('GLOB(0x8eba428)') called at cpanel.pl line 352
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It seems like a RVskin problem.

In addition I have disabled thenative SSL support (stunnel in use) and the memory
which a cPanel process can have is increased to 256MB.